HDMI audio out to AVR problem

Hi James and the community friends!

I have tried everything to connect HDMI to the viewHD HDMI audio extractor (one hdmi out to my projector and the HDMI audio out to my old Denon avr-3806 receiver). The LPCM coming from splitter is always 2 channel even on best audio setting in ATV. I then connected HDMI directly from ATV to Denon then initially got MultiCH PCM but it’s quite finicky working and not working intermittently and the passthrough does not allow 4k anyway, so that option is out the window.

The only other option I feel possible for me is to just use the dolby digital option on ATV.

My question is

  1. when you select this option (and it seems to work perfectly with my viewHD audio extractor even on toslink optical cable outputting Dolby digital signal to denon receiver) does ATV actually “re-encode” the already lossy (original DD is lossy, correct?) signal even further? It sounds analogous to encoding MP3 again to another MP3 file which is one thing that you want to avoid at all cost? If that’s the case I won’t use it. But if it’s at least “passing through” the dolby digital signal untouched and encoding only DTS signal to DD in order for this to work, I’m willing to tolerate it…

  2. I know it’s been discussed, but still there is no news on the horizon of apple ever allowing DTS and DD passthrough from ATV in the future?

I really thought ATV was going to be “the” machine for me, as it sounded like it was decoding every format available to lossless MultiCH which would be perfect for my Denon receiver which I thought would allow all untouched LPCM over HDMI but is no longer the case. I really love infuse for its subtitle ability so willing to forego slight sound loss but just wanted to know for the DD output option whether it’s “reencoding everything” through another lossy process.

Many thanks for your insight.

Unfortunately toslink cable only supports 2 channel PCM so as you found out you would have to re-encode it to DD. The Apple TV will decode the audio without losing quality and I would imagine that you wouldn’t lose quality going from DD lossy in to DD lossy out since it uses the same encoder and decoder. Going from DTS you might since they are different encodings.

I’m surprised that multi channel PCM doesn’t work with your Denon since it is pretty basic and doesn’t require any additional work from the receiver. When you say finicky does it just not play or it doesn’t sound right?

Probably no chance for passthrough. Apple wants to be able to inject modify audio for things like Siri.

Many thanks.

I was surprised too that MultiCH didn’t work, as on 3806 paper everything should work flawlessly. The ONLY time I’ve seen it happen was when I directly connected HDMI to 3806 rather than through viewHD HDMI audio extractor (and yes, on viewHD website they advertise that extracted audio should pass the LPCM signal without any problem but I think I’ve wasted about 6 hours of my valuable life trying to get it to work! :slight_smile:

But then after switching 3806 off and then back on again even on direct connection from ATV to 3806 MultiCH doesn’t work (no input blinkers on at all).

Pity, pity, this would’ve been my perfect setup but it doesn’t work…

Even if direct connection worked I would have quite a headache through 3806’s passthrough HDMI out as it only outputs 1080p at SDR not HDR…

Perhaps you could try a different HDMI cable? Sometimes these cause problems. Also it couple be a problem with your splitter. If it is a recent purchase your might be able to return and try something else?

A lot of HDMI splitters use the EDID that is picked up from the video device. So if the projector doesn’t support multichannel pcm then it won’t pass that through to your receiver (regardless of whether the receiver supports it or not. This is a limitation of cheap sub $150 splitters. You’ll need something by HDFury for proper support

Thanks Jarvis
I’ve got HDMI direct connected to splitter then one HDMI going to projector and another to the Denon so I’m not sure… but perhaps as you suggest the splitter may be bad quality… I think viewHD was not as robust as fury but not sure if I can risk shelling out much more at this stage…

Another option is to get a new receiver that does passthrough HDR. I know this may not be ideal but since your projector doesn’t have HDMI 2.1 you could get a 2018 Denon for much cheaper than the newest models.

Ok… i have now wasted like… 5 days trying to see if permutations of different settings will fix this… I think I’m now sick. Mental breakdown.

Time to buy a new receiver i think.

One question.

So if i buy a new receiver (latest model of Denon whatever it may be), connect ATV4k to it via HDMI, then pass through HDMI out to projector (probably using a cheap HDMI Ethernet extender), should it work? Or should i persist using viewHD? This viewHD HDMI audio extractor was not cheap and I think it’s still the flagship model.

I’m pretty sure Epson 5040ub has HDMI 2.1

It depends on whether the receiver pushes a EDID without being connected to a video source… if it doesn’t you’ll have the same problem using the extractor. Connect everything like a standard setup. Apple TV into the receiver and the receiver into the projector.

At the moment I believe only some 2020 tv models and only lg oled 2019 have full hdmi 2.1 support. It might have some things like VRR or ALLM or eARC which Denon supports on HDMI 2.0b. You shouldn’t need anything between receiver and projector other than HDMI cable (extender if needed)